Photochromic hybrid fabric

ABSTRACT

A photochromic yarn can be formed by combining one or more photochromic dyed synthetic fiber filaments and can be formed by combining one or more photochromic dyed synthetic fiber filaments with one or more natural fiber filaments. A photochromic fabric can be formed by weaving one or more photochromic yarns together and by weaving one or more photochromic yarns with one or more natural fiber yarns. A method of making photochromic yarns and fabrics that have improved photochromic qualities, includes the steps of dyeing, buffer coating, spinning and weaving.

RELATED APPLICATIONS

This application is related to and claims priority from U.S. Provisional Application No. 60/639,979, titled “Photochromic Hybrid Fabric,” filed Dec. 30, 2004, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to the construction of photochromic dyed yarns and fabrics.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EXEMPLARY EMBODIMENTS DETAILED DESCRIPTION OF THE DRAWINGS

This invention is better understood by reading the following detailed description with reference to the accompanying drawings, which are described below:

FIG. 1 shows a composite view of a photochromic yarn according to embodiments of the present invention; and

FIG. 2 illustrates a composite view of a photochromic fabric according to embodiments of the present invention.

BACKGROUND & SUMMARY

Photochromic dyes are special dyes that reversibly change color upon exposure to ultraviolet sources, such as sunlight. Color changes occur at the molecular level. When the light source is removed, the molecules return to their uncolored state. The number of reaction cycles, each of which consists of an activation and a fade period, vary greatly by application. The activation times are generally much shorter than the fade times. On average, fade times are two or three times longer than activation times. The life span governing the number of reaction cycles is limited and is affected by a number of factors including but not limited to the type of yarn or fabric to which the photochromic dye is applied, the method or process used to apply the dye to the yarn or fabric, and the depth to which the dye penetrates the yarn or fabric.

Prior art techniques for creating fabrics with photochromic properties have typically applied photochromic dye to post-mill (i.e., post-manufactured) fabrics. Typically a garment dyeing approach is used whereby a photochromic dye is applied to the finished garment. Two limitations of such techniques are the following: fabric options are generally limited to synthetic materials and the dyed fabrics have short photochromic life spans, which may be on the order of a few hours up to a few weeks of light exposure, due to the superficial application of the dye.

An objective of the present invention is to improve upon the performance of prior art techniques for making photochromic yarns and fabrics. Dye-Buffer-Spin-Weave (DBSW) construction, according to embodiments of the present invention, defines a new process for creating photochromic dyed yarns and fabrics, allowing for the production of multifilament, mixed natural and synthetic yarns and fabrics that have improved photochromic life spans.

Description

Photochromic Yarn

FIG. 1 shows a woven photochromic multifilament yarn fragment 10 according to embodiments of the present invention. As shown in FIG. 1, the photochromic yarn is comprised of a natural fiber filament 11, a synthetic fiber filament 12, and a synthetic fiber filament 13. The natural fiber filament 11 and the synthetic fiber filament 12 are wrapped around the synthetic fiber filament core 13 in a process that is sometimes referred to as core-spinning.

One of skill in the art will realize that in some embodiments of the present invention other weave patterns for the natural fiber filament 11, the synthetic fiber filament 12, and the synthetic fiber filament 13 of the photochromic yarn 10 are possible.

The natural fiber portion 11 of the photochromic yarn 10 can be composed of cotton, wool, camel hair, linen, silk, other natural fibers, or any combination of natural fibers.

In some presently preferred embodiments, the natural fiber portion 11 of the photochromic yarn 10 is composed of a ring-spun cotton filament.

The synthetic portions 12 and 13 of the photochromic yarn 10 can be composed of acetate, acrylic, rayon, modal, elastane, e.g., Spandex®, polyester, aramid, nylon, olefin, optical fiber, or other synthetic fibers. ® Spandex is a registered trademark of Dupont, Inc.

In a presently preferred embodiment, the synthetic portion 12 of the photochromic yarn 10 is composed of a Kevlar® brand aramid filament, which has been dyed with a Photosol® brand photochromic dye, and the synthetic portion 13 of the photochromic yarn 10 is composed of a RadiciSpandex S-17B polyether-based Spandex/elastane filament. ® Kevlar is a registered trademark of Dupont, Inc. ® Photosol is a registered trademark of PPG Industries, Inc.

In an exemplary embodiment of the present invention, the synthetic portion 12 of the photochromic yarn 10 is composed of a 62.5/125 micron multimode optical fiber filament, which has been dyed with a Photosol brand photochromic dye, and the synthetic portion 13 of the photochromic yarn 10 is composed of a RadiciSpandex S-17B polyether-based Spandex/elastane filament.

In a presently preferred embodiment, a ring-spun cotton filament and a photochromic dyed aramid filament are wrapped (or core spun) around an elastane filament core to create a “stretch” photochromic dyed yarn.

In one implementation, a ring-spun cotton filament and a photochromic dyed 62.5/125 micron multimode optical fiber filament are wrapped (or core spun) around an elastane filament core to create a “stretch” photochromic dyed yarn.

Those of ordinary skill in the art will recognize that in some embodiments of the present invention the two synthetic filaments 12 and 13 of the photochromic yarn 10 in FIG. 1 may be respectively composed of the same material and may be respectively composed of dissimilar materials.

One of ordinary skill in the art will also recognize that in other exemplary embodiments of the current invention different natural filament and synthetic filament combinations are possible and that the number of filaments that comprise a photochromic yarn can be less than or greater than the three filaments shown in FIG. 1.

Photochromic Fabric

FIG. 2 shows a photochromic fabric fragment 20 according to embodiments of the present invention. As illustrated in FIG. 2, the photochromic fabric 20 is comprised of two yarns: one designated as warp 21 and one designated as weft 22. The warp yarn 21 runs parallel to the selvage or woven edge portion of a fabric. The weft yarn 22 is woven through the warp yarn 21 and runs crosswise from one selvage 23 to the other selvage 23 of the fabric. The weft yarn may be woven perpendicular (forming a 90° angle) to the warp yarn in a fabric, or the weft yarn 22 may be woven on a diagonal to the warp yarn 21 as shown in FIG. 2.

Presently preferred example yarn combinations for the photochromic fabric 20 shown in FIG. 2 are listed in Table 1. One of ordinary skill in the art will realize that for other embodiments of the current invention different warp yarn 21 and weft yarn 22 combinations than those shown in Table 1 are possible. TABLE 1 Warp Weft Natural fiber yarn Photochromic yarn 50% natural yarn and 50% photochromic Photochromic yarn yarn Photochromic yarn Natural fiber yarn

A presently preferred embodiment of the current invention is a photochromic stretch denim fabric comprised of a ring-spun cotton fiber warp yarn 21 and a photochromic weft yarn 22, the photochromic yarn being composed of a Kevlar brand aramid filament 12 and cotton filament 11 that are core spun around a RadiciSpandex brand elastane filament core 13.

In an exemplary embodiment of the present invention, the weft yarn 22 of the photochromic stretch denim fabric is composed of a cotton filament 11 and a 62.5/125 micron multimode optical fiber filament 12 that are together core spun around a RadiciSpandex brand elastane filament core 13. The warp yarn 21 is composed of ring spun cotton.

One of ordinary skill in the art will realize that the warp yarn 21 and weft yarn 22 of the photochromic fabric 20 in FIG. 2 are not limited to and in fact can be composed of other materials than those materials specified in the presently preferred and exemplary embodiments described above.

One of ordinary skill in the art will realize that other photochromic fabric options are possible beyond the photochromic stretch denim fabric described above.

Dye-Buffer-Spin-Weave (DBSW) Process

According to embodiments of the current invention, the “Dye-Buffer-Spin-Weave,” or DBSW process is a method for creating mixed (or blended) natural and synthetic yarns and fabrics that have improved photochromic properties.

The DBSW process includes the following steps:

Dye: A photochromic dye is applied to one or more synthetic filaments that are to be part of a photochromic yarn.

Buffer: The dyed filaments are buffer coated with a clear synthetic material, e.g., acrylic, to protect the dyed filaments both during and after the spinning and weaving steps of the process.

Spin: The dyed and buffered filaments are spun together, or optionally spun with natural fiber filaments, which may have been previously dyed using a traditional means, e.g., rope-dyeing, to create a photochromic yarn which has properties of the dyed synthetic fiber filaments and has properties of the natural fiber filaments, e.g., “hand/feel,” if natural fiber filaments are optionally spun with the synthetic fiber filaments.

Weave: The created photochromic yarns can be woven together or weaved with natural fiber yarns to create a photochromic fabric, which in turn can be used to make finished garments having improved photochromic properties.

In a presently preferred embodiment of the DBSW method, Kevlar brand aramid (synthetic) filaments are twisted into a rope before being dipped into a Photosol brand photochromic dye. The photochromic dyed filaments are then coated, or buffered with a clear color acrylic, having a thickness of less than 100 microns. The photochromic dyed and buffered aramid filaments and ring-spun natural cotton filaments are then together core spun around a RadiciSpandex S-17B polyether-based Spandex/elastane filament core to form a photochromic yarn. The photochromic yarn (weft) is then woven with a natural cotton yarn (warp), using a “one-up and one-down” pattern, to create a photochromic stretch denim fabric.

One of ordinary skill in the art will realize that variations of the above stated preferred embodiment of the DBSW method are possible and include, but are not limited to the following: other synthetic filaments may be used; different combinations of synthetic and natural filaments may be used to create the photochromic yarn; other buffer materials, e.g., rayon, may be used to protect the photochromic yarn; the thickness of the buffer coating may be thinner or thicker than 100 microns; and different combinations of natural yarns and photochromic yarns may be woven together using different weaving techniques.

Thus are described photochromic yarns and fabrics and methods of making the same. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it should be understood that the invention is not limited by the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. 

1. A photochromic yarn comprising: one or more natural fiber components, composed of one or more natural fiber filaments; and one or more synthetic fiber components, composed of one or more synthetic filaments; wherein the synthetic fiber components are dyed with a photochromic dye during the yarn manufacturing process.
 2. A natural fiber component as in claim 1 wherein the natural fiber component is composed of one or more materials selected from the group comprising: cotton, wool, camel hair, linen, and silk.
 3. A synthetic fiber component as in claim 1 wherein the synthetic fiber component is composed of one or more materials selected from the group comprising: acetate, acrylic, aramid, elastane, modal, nylon, olefin, optical fiber, and rayon.
 4. A natural fiber component as in claim 2 wherein the natural fiber component is cotton.
 5. A synthetic fiber component as in claim 3 wherein the synthetic fiber component is Kevlar brand aramid.
 6. A synthetic fiber component as in claim 3 wherein the synthetic fiber component is a 62.5/125 micron multimode optical fiber.
 7. A photochromic stretch yarn comprising: a natural fiber component composed of one or more natural fiber filaments selected from among cotton, wool, camel hair, linen, silk, and other natural fiber filaments; a first synthetic component composed of one or more synthetic fiber filaments selected from among acetate, acrylic, aramid, elastane, modal, nylon, olefin, optical fiber, rayon, and other synthetic fiber filaments, and wherein the first synthetic component is dyed with a photochromic dye during the yarn manufacturing process; and a second synthetic component composed of elastane or another stretch fiber filament; wherein the natural fiber component and the first synthetic fiber component are together wrapped around the second synthetic fiber component.
 8. A photochromic fabric comprising: one or more photochromic yarns, each yarn composed of at least one photochromic dyed synthetic filament; wherein the photochromic yarns are woven together to create a photochromic fabric.
 9. A photochromic fabric comprising: at least one photochromic yarn composed of at least one photochromic dyed synthetic filament; and at least one natural fiber yarn composed of natural fiber filaments; and wherein the photochromic yarn and the natural fiber yarn are woven together to create a photochromic fabric.
 10. A photochromic fabric as in claim 9 comprising: a “stretch” photochromic yarn, composed of a ring-spun cotton filament and a photochromic dyed aramid filament, that are together wrapped around an elastane filament core; and a natural fiber yarn, composed of ring-spun cotton filaments; and wherein the photochromic yarn and the cotton fiber yarn are woven together to create a stretch photochromic fabric.
 11. A photochromic fabric as in claim 9 comprising: a “stretch” photochromic yarn, composed of a ring-spun cotton filament and a photochromic dyed 62.5/125 micron multimode optical fiber filament, that are together wrapped around an elastane filament core; and a natural fiber yarn, composed of ring-spun cotton filaments; and wherein the photochromic yarn and the cotton fiber yarn are woven together to create a stretch photochromic fabric.
 12. A method of making a photochromic yarn, the method comprising: dyeing one or more synthetic filaments with a photochromic dye; applying a protective buffer coat to the photochromic dyed filaments; and combining the dyed and buffer coated filaments together to form a photochromic yarn.
 13. A method as in claim 12 wherein the synthetic filaments are twisted together in a rope before being dipped into a photochromic dye.
 14. A method as in claim 12 wherein the buffer coat is applied to the individual photochromic dyed filaments, and the buffered filaments allowed to completely dry before further manufacturing processing.
 15. A method as in claim 12 wherein the buffer coat material is selected from among acetate, acrylic, neoprene, nitrile, polystyrene, rayon, and urethane; and wherein the buffer coat is applied to a thickness of less than 100 microns.
 16. A method of making a photochromic fabric, the method comprising: dyeing one or more synthetic filaments with a photochromic dye; applying a protective buffer coat to the photochromic dyed filaments; combining the dyed and buffer coated filaments together to form a photochromic yarn; and weaving the photochromic yarns together create a photochromic fabric.
 17. A method as in claim 16 wherein the synthetic filaments are twisted together in a rope before being dipped into a photochromic dye.
 18. A method as in claim 16 wherein the buffer coat is applied to the individual photochromic dyed filaments, and the buffered filaments allowed to completely dry before further manufacturing processing.
 19. A method as in claim 16 wherein one or more photochromic yarns are woven together with one or more natural fiber yarns to make a photochromic fabric.
 20. A method as in claim 12 wherein the buffer coat material is selected from among acetate, acrylic, neoprene, nitrile, polystyrene, rayon, and urethane; and wherein the buffer coat is applied to a thickness of less than 100 microns. 